At present, a display screen is usually supported by a lifting support, the lifting support comprises a stand column and a lifting seat, and the display screen is disposed on the stand column via the lifting seat with its height being adjustable.
A constant force spring (a type of wind spring) is disposed between the stand column and the lifting seat, and arbitrary stopping of the display screen during the adjustment of its height can be achieved by means of the constant force spring.
In order to meet the requirement of ultra-thinning development of stand column, those skilled in the art have attempted to replace the existing single-layer constant force spring with a multilayer wind spring, so as to effectively reduce the space occupied by the constant force spring in the stand column, thereby meeting the requirement of ultra-thinning of the stand column.
However, the multilayer wind spring has very short service life. An arching phenomenon of an inner-layer metal sheet frequently occurs during its use. Once the inner-layer metal sheet arches, the multilayer wind spring can no longer be used normally and has to be replaced, thereby resulting in bad user experience while increasing the maintenance cost.
In the prior art, it is necessary to apply a lubricating oil between two adjacent elastic metal sheets, so as to avoid the arching phenomenon to the greatest extent for a long period of time during the use of the multilayer wind spring. The process of manufacturing the multilayer wind spring comprises making elastic metal sheets by rolling forming and heat treatment, and finally combining the multiple elastic metal sheets into a multilayer wind spring by a spring-combining (making) machine. Since the applied lubricating oil is washed away during the heat treatment, the lubricating oil must be applied during the spring-combining process. However, since the elastic metal sheets have all been formed by pressing at this moment, the oil application procedure is complicated with low efficiency.